This invention relates to a system for preventing physical deterioration of the muscles of severely injured patients. A serious injury may cause permanent spinal injury resulting in paraplegia or quadriplegia. The resulting prolonged disuse of the limbs produces atrophy of the muscles, deterioration of the tendons and osteoporosis in the bones. As the bones and muscles begin to decondition, there is a reduction in circulation of the blood, thereby predisposing the patient to pressure sores and blood clots.
It has been found that such physical deterioration can be reversed, even after years of muscular disuse, through a physical conditioning program based upon functional electrical stimulation of the paralyzed muscle. Typical apparatus for producing appropriate muscular stimulation is disclosed in Petrofsky et al U.S. Pat. No. 4,421,336 and includes pairs of alternately pulsed electrodes which may be applied to the surface of the skin above those muscles which are to be stimulated. Such stimulation devices have been used to stimulate operation of wheelchairs, tricycles, exercise bicycles and exercise chairs equipped with leg weights. Such systems have produced remarkable rehabilitation of long term paraplegic and quadriplegic patients.
It is known that the effects of muscle disuse begin to manifest themselves almost immediately upon cessation of muscular activity. The above-described prior art devices may be used only by persons who have recovered from the trauma of their injury and have regained a relatively stable physical condition. In the interim, however, such persons may have experienced a long period of physical inactivity during which muscular deterioration has commenced. If the injured person is in a state of coma, the inactivity may continue for many months. It is therefore seen that there is a need for a system to provide physical therapy for such acutely injured persons prior to the time when use of the above-mentioned prior art devices becomes appropriate.